package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import jdk.nashorn.internal.ir.CallNode;
import org.springframework.aop.framework.AopContext;
import org.springframework.aop.framework.AopProxy;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author lib
 * @since 2025-09-16
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    
    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券信息
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.1判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())){
            //没开始，返回异常结果
            return Result.fail("秒杀尚未开始");
        }
        //2.2判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())){
            //秒杀已结束，返回异常结果
            return Result.fail("秒杀已结束");
        }
        //3.判断库存是否充足
        //3.1缺货，返回异常结果
        if (voucher.getStock() < 1){
            return Result.fail("缺货");
        }

        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        SimpleRedisLock lock = new SimpleRedisLock(stringRedisTemplate,"order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock(1200);
        //判断是否获取锁
        if (!isLock){
            //获取锁失败
            return Result.fail("不允许重复下单");
        }

        try {
            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
            return proxy.creatVoucherOrder(voucherId);
        } finally {
            //释放锁
            lock.unLock();
        }

    }

    @Transactional
    public Result creatVoucherOrder(Long voucherId) {
        //4.一人一单
        Long userId = UserHolder.getUser().getId();
        //4.1查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        //4.2判断是否存在
        if (count > 0){
            //用户已经购买过
            return Result.fail("用户已经购买过");
        }

        //5扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherId).gt("stock",0).update();  //id,stock
        if (!success){
            //库存不足
            return Result.fail("库存不足");
        }
        //6.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        //6.1订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //6.2用户id
        voucherOrder.setUserId(userId);
        //6.3代金券id
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        //7.返回订单id
        return Result.ok(orderId);
    }
}
